Question

Functional units of food absorption are

• A. Villi
• B. Brunners glands
• C. Crypts of Lieberkuhn
• D. Peyers patches

Answer 1

The correct option is A Villi

The villi and microvilli, with their many folds with finger-like projection, present on the lining of the small intestine, increase the surface area of the intestine for more absorption of the nutrients. The microvilli have protein channels and pumps in their membranes to allow the rapid absorption of food by facilitated diffusion and active transport. Also, the villi contain an epithelial layer, which is only one cell layer thick so that food can pass through easily and be absorbed quickly. This thin layer of cells contains mitochondria to provide the ATP needed for the active transport of certain food molecules. Finally, there is a lacteal branch at the centre of the villus, which carries away fats after absorption.

So, the correct answer is option A.